1. Field of the Invention
The present invention relates to cardiac catheter devices and more particularly to an improved method and apparatus for eliminating a constriction or narrowing of a patient's carotid artery.
2. General Background
Atherosclerotic stenosis of the extracranial carotid arteries (the arteries on each side of the neck that supply blood to the head and neck) causes a significant portion of the 500,000 strokes that occur each year in the U.S. The superiority of carotid endarterectomy over medical management has been clearly demonstrated in symptomatic patients. Recently, the Asymptomatic Carotid Atherosclerosis Study showed a marked reduction in the incidence of stroke following carotid endarterectomy in asymptomatic carotid stenosis of &gt;60%. These studies have provided clear evidence of the benefit of revascularization of the diseased extracranial carotid artery. Carotid endarterectomy is performed now surgically through an artery in the patient's neck.
Surgery, however, has several limitations. In patients with angina, morbidity and mortality rates as high as 18% have been reported. Endarterectomy is generally confined to the cervical portion of the carotid artery. Cranial nerve palsies occur in 7.6% to 27% of patients. Restenosis after endarterectomy appears to occur in 10% to 19% of patients.
Percutaneous techniques have the potential for being safer, less traumatic, more cost effective, usable in patients at high surgical risk, and are not limited to the cervical carotid artery. These potential benefits, however, have yet to be realized for the general population of patients with carotid disease even though percutaneous carotid balloon angioplasty (PCBA) was first performed in 1980. Angioplasty is a procedure for alleviating blockage of an artery in which a balloon tipped catheter is threaded into an artery to a point of obstruction and inflated to push the vessel open.
Surgeons are presently using catheters designed for coronary angioplasty and peripheral angioplasty. Thus, there exists a need for a catheter system specifically designed for carotid arteries.
U.S. Pat. No. 5,449,362 and prior applications, PCT Application no. PCT/US95/06205, and all patents mentioned herein and therein, are incorporated herein by reference.